Handle locking attachment for electrical control devices



Dec. 13, 1966 a J. A. THARP 3,291,924

HANDLE LOCKING ATTACHMENT FOR ELECTRICAL CONTROL DEVICES Filed Feb. 25, 1965 United States Patent 3,291,924 HANDLE LOCKING ATTACHMENT FOR ELECTRICAL CONTROL DEVICES James A. Tharp, Cedar Rapids, Iowa, assignor to Square D Company, Park Ridge, Ill., a corporation of Michigan Filed Feb. 25, 1965, Ser. No. 435,242 4 Claims. (Cl. 200-42) This invention relates to a handle locking. attachment for electrical control devices such as switches and molded-case circuit breakers.

An object of the invention is to provide a padlock- Ieceiving type of handle locking attachment which is readily clampable directly to a pivotable operating handle extending outwardly of a casing of .an electrical control device to lock the handle in one of two operative positions thereof.

Other objects and advantages will become apparent when the following specification is considered along with the accompanying drawings in which:

FIG. 1 is a fragmentary perspective view of a circuit breaker having a handle locking attachment constructed in accordance with the invention secured to a pivotable operating handle thereof;

FIG. 2 is a sectional view taken generally along the line 2-2 of FIG. 1;

FIG. '3 is a sectional view taken generally along the line 3-3 of FIG. 2;

FIG. 4 is a front view of the-handle locking attachment of FIG. 1;

FIG. 5 is a side view of the handle locking attachment of FIG. 1;

FIG. 6 is a perspective view of the clamping member of the handle locking attachment of FIG. 1; and

FIG. 7 is a perspective view of the housing member of the handle locking attachment of FIG. 1.

A handle locking attachment 10 constructed in accordance with the invention may be used on circuit breakers such as disclosed in US. patent application, Serial No. 246,522, filed on December 21, 1962, and also on various other circuit breakers and switches.

FIGS. 1-3 show a casing 12 of a circuit breaker having a pivotable operating handle 14 extending outwardly of the casing through a suitable aperture. The casing 12 is provided with suitable indicia to indicate ON and OFF operative positions of the handle. The handle looking attachment 10 may be secured directly to the handle 14 and includes a generally U-shaped housing member 16 (best shown in FIG. 7) having a bight portion 18 and a pair of generally parallel leg portions 19 and 20. Preferably the leg portions 19 and 20 are inwardly offset by otfsetting portions 21 and 22 to provide a pair of inwardly offset portions 23 and 24. The bight portion 18 is lanced inwardly to provide a biting edge 25.

The handle locking attachment 10 also includes a generally U-shaped clamping member 28 (best shown in FIG. 6) fitting between the inwardly offset portions 23 and 24 and having a bight portion 30* and [a pair of generally parallel leg portions 31 and 32. The clamping member 28 is pivotally mounted with respect to the housing member 16 by means of a rivet 34 or other suitable fastening means extending through a pair of aligned openings 31a and 32a provided respectively in the leg portions 31 and 32 of the clamping member 28 and through a pair of aligned openings 23a and 24a provided respectively in the oifset portions 23 and 24 of the leg portions 19 and 20 of the housing member 16. The rivet 34 is disposed adjacent the offsetting portions 21 and 22 and adjacent the free ends of the leg portions 3 1 and 32. For the purpose hereinafter set 3,291,924 Patented Dec. 13, 1966 forth, the free ends of the leg portions 31 and 32 are formed to provide curved surfaces 31b and 32b of varying radius measured from the axis of the rivet 34.

In the attaching of the handle locking attachment 10 to the handle 14, the enlarged bight end portion of the housing member 16 is slipped over the outer end portion of the handle 14 while the clamping member 28 is in a position relative to the housing member 16 as indicated by broken lines in FIGS. 1-3. The clamping member 28 is then pivoted relatively to the housing member 16 to a handle clamping position indicated by full lines in FIGS. 1-3. As the clamping. member 28 is pivoted from the broken line position to the full line position, the distance between the bight portion 18 and the leg portions 31 and 32 decreases because of the aforementioned varying radius of the curved surfaces 31b and 32b defining the free ends of the leg portions 31 and 32, and the handle 14 is thus clamped between the bight portion 18 and the free ends of the leg portions 31 and 32. A padlock 36 may then be secured in place on the handle locking attachment 10 to maintain the clamping member 28 in handle clamping position by inserting a shackle 37 of the padlock through a pair of holes 38 and 39 provided respectively in the portions 23 and 24 of the housing member 16 adjacent the free ends thereof and through :a pair of holes 40 and 41 provided respectively in the leg portions 31 and 32 of the clamping member 28 adjacent the bight portion 30 thereof.

The offset portions 23 and 24 of the housing member 16 may be provided respectively with a pair of projections 43 and 44 adapted to extend into the handleaperture of the casing 12 .as shown in FIG. 3. Further, the offset portions 23 and 24 are formed to extend at an acute angle .to the bight portion 18, so that when the attachment 10 is clamped on the handle 14 when the handle is in one of its operative positions and an attempt is made to pivot it to the other of its operative positions, the offset portions 23 and 24 will bear against the casing 12.

If desired, a pair of holes 45 and 46 may be provided respectively in the offset portions 23 :and 24 of the housing member 16 and a pair of holes 47 and 48 may be provided respectively in the leg portions 31 and 32 of the clamping member 28 for the reception of a sealing wire (not shown).

It will be seen that I have provided a simply construeted handle locking attachment which is readily secured on a pivotable operating handle merely by slipping the housing member 16 on the handle and flipping the clamping member 28 into clamping position. The biting edge 25 aids in retaining the attachment on the handle.

Various modifications may be made in the structure shown and described without departing from the spirit and scope of the invention.

I claim:

1. A handle locking attachment securable to a pivotable operating handle extending outwardly of a casing of an electrical control device to lock the handle in one of two operative positions thereof, said attachment comprising a generally U-shaped housing member formed from flat sheet stock and including a bight portion and a pair of spaced, flatwise generally parallel leg portions, a generally U-shaped clamping member formed from flat sheet stock and including a bight portion and a pair of spaced, flatwise generally parallel leg portions, the leg portions of said clamping member being disposed between the leg portions of said housing member, and means connecting said clamping and housing members for pivotal movement relative to each other about .a fixed axis extending generally perpendicularly to the leg portions of said clamping and housing members and disposed adjacent the free ends of the leg portions of said contr ol device when said handle =locking attachment is clamping member 'in'spaced 'relationshipto the bight portion of said housing member, said free ends of the leg portions of said clamping member being defined respectively by curved edge surfiaces of varying radius measured from said fixed axis of pivotal movement be tween said'clamping and housing members, the distance between said bight portion of said housing member and said free ends of the leg portions of said clamping member decreasing due to the varying radius of said curved edge surfaces as said clamping member is pivoted relatively to said housing member from a position in which the leg portions 'of said clamping member extend generally perpendicularly to the :leg portions of said housing member to a position in which the leg portions of said clamping member are substantially aligned with the leg portions of said housing member, whereby a pivotable operating handle extending outwandly of a casing of an electrical control device may be clamped between said bight portion of said housing member and said free ends of said leg portions of said clamping member, the free end portions of the leg portions of said housing member and the bight end portions of the leg portions of said clamping member having apertures extending respectively therethrough which are aligned When said clamping member is in clamping position relatively to said housing member for receiving a shackle of a padlock to lock said clamping member in said clamping secured on a pivotable operating handle thereof and said handle is in one of two operative positions and an attempt is made to pivot-said handle to the other operatirve position there-of. 1

2. A handle locking attachment as claimed in claim T1, wherein the leg portions of said housing member are inwardly offset adjacent said fixed axis of pivotal movement between said clamping and housing members and on the side of said axis toward said bight portion of said housing member. I

3. A handle locking attachment as claimed in claim 1, wherein said bight portion of said housing member is lanced to provide a biting edge which aids in retaining said attachment on a handle when said handle is clamped therein.

4. A handle locking attachment as claimed in claim [1, wherein the leg portions of one of said members are provided respectively with a pair of projections receivable in the handle aperture of an electrical control de vice when said attachment is mounted on the handle thereof.

No references cited.

ROBERT K. SCI-IAEFER, Primary Examiner.

30 H. HOHAUSER, Assistant Examiner. 

1. A HANDLE LOCKING ATTACHMENT SECURABLE TO PIVOTABLE OPERATING HANDLE EXTENDING OUTWARDLY OF A CASING OF AN ELECTRICAL CONTROL DEVICE TO LOCK THE HANDLE IN ONE OF TWO OPERATIVE POSITIONS THEREOF SAID ATTACHEMENT COMPRISING A GENERALLY U-SHAPED HOUSING MEMBER FORMED FROM FLAT SHEET STOCK AND INCLUDING A BIGHT PORTION AND A PAIR OF SPACED, FLATWISE GENERALLY PARALLEL LEG PORTIONS, A GENERALLY U-SHAPED CLAMPING MEMBER FORMED FROM FLAT SHEET STOCK AND INCLUDING A BIGHT PORTION AND A PAIR OF SPACED, FLATWISE GENERALLY PARALLEL LEG PORTIONS THE LEG PORTIONS OF SAID CLAMPING MEMBER BEING DISPOSED BETWEEN THE LEG PORTIONS OF SAID HOUSING MEMBER, AND MEANS CONNECTING SAID CLAMPING AND HOUSING MEMBERS FOR PIVOTAL MOVEMENT RELATIVE TO EACH OTHER ABOUT A FIXED AXIS EXTENDING GENERALY PERPENDICULARLY TO THE LEG PORTIONS OF SAID CLAMPING AND HOUSING MEMBERS AND DISPOSED ADJACENT THE FREE ENDS OF THE LEG PORTIONS OF SAID CLAMPING MEMBER IN SPACED RELATIONSHIP TO THE BIGHT PORTION OF SAID HOUSING MEMBER, SAID FREE ENDS OF THE LEG PORTIONS OF SAID CLAMPING MEMBER BEING DEFINED RESPECTIVELY BY CURVED EDGE SURFACES OF VARYING RADIUS MEASURED FROM SAID FIXED AXIS OF PIVOTAL MOVEMENT BETWEEN SAID CLAMPING AND HOUSING MEMBERS, THE DISTANCE BETWEEN SAID BIGHT PORTION OF SAID HOUSNG MEMBER AND SAID FREE ENDS OF THE LEG PORTIONS OF SAID CLAMPING MEMBER DECREASING DUE TO THHE VARYING RADIUS OF SAID CURVED EDGE SURFACES AS SAID CLAMPING MEMBER IS PIVOTED RELATIVELY TO SAID HOUSING MEMBER FROM A POSITION IN WHICH THE LEG PORTIONS OF THE SAID CLAMPING MEMBER EXTEND GENERALLY PERPENDICULARLY TO THE LEG PORTIONS OF SAID HOUSING MEMBVER OT A POSITION IN WHICH THE LEG PORTIONS OF SAID CLAMPING MEMBER ARE SUBSTANTIALLY ALIGNED WITH THE LEG PORTIONS OF SAID HOUSING MEMBER, WHEREBY A PIVOTABLE OPERATING HANDLE EXTENDING OUTWARDLY OF A CASING OF AN ELECTRICAL CONTROL DEVICE MAY BE CLAMPED BETWEEN SAID BIGHT PORTION OF SAID HOUSING MEMBER AND SAID FREE ENDS OF SAID LEG PORTIONS OF SAID CLAMPING MEMBER, THE FREE END PORTIONS OF THE LEG PORTIONS OF SAID HOUSING MEMBER AND THE BIGHT END PORTIONS OF THE LEG PORTIONS OF SAID CLAMPING MEMBER HAVING APERTURES EXTENDING RESPECTIVELY THERETHROUGH WHICH ARE ALIGNED WHEN SAID CLAMPING MEMBER IS IN CLAMPING POSITION RELATIVELY TO SAID HOUSING MEMBER FOR RECEIVING A SHACKLE OF A PADLOCK TO LOCK SAID CLAMPING MEMBER IN SAID CLAMPING POSITION, AND THE LEG PORTIONS OF SAID HOUSING MEMBER BEING FORMED TO BEAR AGAINST THE CASING OF AN ELECTRICAL CONTROL DEVICE WHEN SAID HANDLE LICKING ATTACHMENT IS SECURED ON A PIVOTABLE OPERATING HANDLE THEREOF AND SAID HANDLE IS IN ONE OF TWO OPERATIVE POSITIONS AND AN ATTEMPT IS MADE TO PIVOT SAID HANDLE TO THE OPERATIVE POSITION THEREOF. 